/*
 * MIT License
 *
 * Copyright (c) 2020 Shreyas Patil
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package dev.shreyaspatil.foodium.model

import dev.shreyaspatil.foodium.data.repository.Resource

/**
 * State Management for UI & Data.
 */
sealed class State<T> {
    class Loading<T> : State<T>()

    data class Success<T>(val data: T) : State<T>()

    data class Error<T>(val message: String) : State<T>()

    fun isLoading(): Boolean = this is Loading

    fun isSuccessful(): Boolean = this is Success

    fun isFailed(): Boolean = this is Error

    companion object {

        /**
         * Returns [State.Loading] instance.
         */
        fun <T> loading() = Loading<T>()

        /**
         * Returns [State.Success] instance.
         * @param data Data to emit with status.
         */
        fun <T> success(data: T) =
            Success(data)

        /**
         * Returns [State.Error] instance.
         * @param message Description of failure.
         */
        fun <T> error(message: String) =
            Error<T>(message)

        /**
         * Returns [State] from [Resource]
         */
        fun <T> fromResource(resource: Resource<T>): State<T> = when (resource) {
            is Resource.Success -> success(resource.data)
            is Resource.Failed -> error(resource.message)
        }
    }
}
